Parsing
• Just & Carpenter (1980) theorized that when we encounter a word we access its meaning from LTM, identify its referent, and fit it into the syntactic structure of a sentence, called the immediacy principle • The alternative is to postpone interpretation of the word and/or phrase until there is more information, called the wait-and-see approach • Because the # of decisions that need to be made for a typical sentence is very large, it seems logical to deal with each decision as it appears, rather that stacking the problems up for later • (1) John bought flowers for Susan • If we wait-and-see, we have 2 interpretations to hold
• Trueswell, Tanenhuas, & Garnsey (1994) found evidence that lexical information does influence syntactic parsing • They examined eye fixations to sentences; 19 & 20, p. 136 • When the animate subject was used, eye fixations were longer • This is a type of garden path sentence; your first interpretation is not the correct one • Typically you assume that the animate subject is doing the action (e.g., examining) • Instead, it is the subject that is being examined • When you have an inanimate subject (e.g., evidence), the reader knows that is cannot perform the action; thus, the garden path is not traveled and the correct interpretation is made with the initial parsing
Modular or Interactive?
• Thus, there is evidence that the syntactic parser is not completely modular and not completely interactive • The current evidence suggests that lexical information does influence the syntactic parser • However, discourse (paragraph context) does not influence the syntactic parser • Readers seem to quickly use information about the kinds of syntactic structures in which various words are likely to participate
Modular vs. Interactive Models
• These can be examined with structurally ambiguous sentences • (11) The florist sent the flowers was very pleased. • The parsing favored by the minimal attachment principle is that sent is the verb, as in (12) • (12) The florist sent the flowers to the elderly widow. • The other interpretation is a reduced relative clause, (13) • (13) The florist who was sent the flowers was very pleased • The ambiguity occurs because English permits the reduction or deletion of relative clauses such as who was • Does information about real world events influence our parsing of a sentence? Rayner et al. (1983) found eye fixations were long for both garden path sentences 11 & 14 • (14) The performer sent the flowers was very pleased.
• Minimal Attachment Strategy
– Attach new items into the phrase marker being constructed using the fewest syntactic nodes – e.g., (9) & (10); see Figure 6-2, p. 134; – Frazier & Rayner (1982) found that reading times were faster for (9) than for (10); this is because building an additional constituent takes more time than attaching it to the current constituent
Sentence Comprehension
• • • • Parsing Immediacy Principle Parsing Strategies Modular vs. Interactive Models
• One view of comprehending sentences is that part of understanding the meaning of a sentence involves parsing it into its syntactic constituents • This results in some type of representation of these constituents in working memory; e.g., an analog of a tree diagram; see Figure 6-1 on p. 131 • When we encounter the word “the” we recognize that it is a determiner and typically indicates the beginning of a noun phrase; NP det + (adj) + N • After reading or hearing “the” we are expecting an adjective or a noun • This process is a series of decisions; it is a type of problem solving
• Modular models assume that there are separate processing units that perform a specific function and cannot be interfered with by other processing units • Interactive models assume that processing units interact with each other, such that one unit may affect processing performed by another unit • One view is that parsing is performed as a syntactic module, and it is not influenced by semantic processing or general world knowledge • An alternative view is that syntax and semantics interact during sentence comprehension • Constraint-based model: we simultaneously use all available information in our initial parsing: syntax, lexical, discourse, & non-linguistic context
• Ferreira & Clifton (1986) found that the parser operates with structural biases that are not influenced by prior semantic context • The gave Ss sentences that could & could not be parsed by means of minimal attachment • Sometimes the paragraph context biased the reader toward a minimal attachment interpretation of the target sentence • Other times the context primed the non-minimal attachment • They found that readers continued to use the minimal attachment principle, even when the context biased the nonminimal attachment • This indicates that discourse does not interact with syntactic parsing